CPR is an emergency procedure performed in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person in cardiac arrest. CPR involves chest compressions at least 5 cm (2 inches) deep and at a rate of at least 100 per minute in an effort to create artificial circulation by manually pumping blood through the heart. Current recommendations place emphasis on high-quality chest compressions over artificial respiration. A simplified CPR method involving chest compressions only is recommended for untrained rescuers. Compression-only (hands-only or cardio cerebral resuscitation) CPR is a technique that involves chest compressions without artificial respiration. It is recommended as the method of choice for the untrained rescuer or those who are not proficient as it is easier to perform and instructions are easier to give over the phone.
Audible and visual prompting may improve the quality of CPR and prevent the decrease of compression rate and depth that naturally occurs with fatigue, and to address this potential improvement, a number of devices have been developed to help improve CPR technique.
Currently, these items can be devices to be placed on top of the chest, with the rescuers hands going over the device, and a display or audio feedback giving information on depth, force or rate, or in a wearable format such as a glove. E.g. U.S. Pat. No. 8,317,519 B1 discloses a portable CPR metronome to assist a user in performing CPR according to medically accepted guidelines using audible and visible prompts. Several published evaluations show that such devices may improve the performance of chest compressions. As well as use during actual CPR on a cardiac arrest victim, which relies on the rescuer carrying the device with them, these devices can also be used as part of training programs to improve basic skills in performing correct chest compressions.
Automatic CPR exist which are capable of providing the mechanical force on the patient's chest according to a preprogrammed scheme, when properly setup by a user. However, such devices are only within reach on few locations.
There are several software applications for personal portable devices on the market to assist during CPR. However, all of them either contain only instructions and a quick emergency call to a professional medical help, or require an additional dedicated device to give a feedback on quality of CPR performance. Such software applications may be useless in many real situations, since there is usually no time to go through the instructions on a portable device.